Confirming the least massive members of the Pleiades star cluster
Affiliation
Univ Arizona, Dept Astron, Steward ObservIssue Date
2018-03-21Keywords
brown dwarfsstars: late type
stars: low mass
open clusters and associations: individual: Pleiades
Metadata
Show full item recordPublisher
OXFORD UNIV PRESSCitation
M R Zapatero Osorio, V J S Béjar, N Lodieu, E Manjavacas; Confirming the least massive members of the Pleiades star cluster, Monthly Notices of the Royal Astronomical Society, Volume 475, Issue 1, 21 March 2018, Pages 139–153, https://doi.org/10.1093/mnras/stx3154Rights
© 2017 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
We present optical photometry (i and Z band) and low-resolution spectroscopy (640-1015 nm) of very faint candidate members (J = 20.2-21.2 mag) of the Pleiades star cluster (120 Myr). The main goal is to address their cluster membership via photometric, astrometric, and spectroscopic studies, and to determine the properties of the least massive population of the cluster through the comparison of the data with younger and older spectral counterparts and state-of-the art model atmospheres. We confirm three bona fide Pleiades members that have extremely red optical and infrared colours, effective temperatures of approximate to 1150 and approximate to 1350 K, and masses in the interval 11-20 M-jup, and one additional likely member that shares the same motion as the cluster but does not appear to be as red as the other members with similar brightness. This latter object requires further near-infrared spectroscopy to fully address its membership in the Pleiades. The optical spectra of two bona fide members were classified as L6-L7 and show features of K i, a tentative detection of Cs i, hydrides, and water vapour with an intensity similar to high-gravity dwarfs of related classification despite their young age. The properties of the Pleiades L6-L7 members clearly indicate that very red colours of L dwarfs are not a direct evidence of ages younger than approximate to 100Myr. We also report on the determination of the bolometric corrections for the coolest Pleiades members. These data can be used to interpret the observations of the atmospheres of exoplanets orbiting stars.ISSN
0035-87111365-2966
Version
Final published versionSponsors
Spanish Ministry of Economy and Competitivity [AYA2016-79425-C3-2-P, AYA2015-69350-C3-2-P]Additional Links
https://academic.oup.com/mnras/article/475/1/139/4705921ae974a485f413a2113503eed53cd6c53
10.1093/mnras/stx3154